<template>
  <div id="container">
    <el-container class="home-container">
      <!-- 头部区域 -->
      <el-header>
        <div>
          <img src="../assets/img/cart.png" alt="">
          <span>电商后台管理系统</span>
        </div>
        <el-button type="info" @click="logout">退出</el-button>
      </el-header>
      <!-- 页面主题区域 -->
      <el-container>
        <!-- 侧边栏 -->
        <el-aside :width="isCollapse ? '64px' : '200px' ">
          <div class="toggle-button" @click="toggleCollapse">|||</div>
          <el-menu
            background-color="#333744"
            text-color="#fff"
            active-text-color="#409eff" unique-opened :collapse="isCollapse" :collapse-transition="false" router
            :default-active="activePath">
            <!-- 一级菜单 -->
            <el-submenu :index="item.id + ''" 
              v-for="item in menulist" 
              :key="item.id"
              >
              <!-- 一级菜单的模板区域 -->
              <template slot="title">
                <!-- 图标 -->
                <i class="el-icon-location"></i>
                <!-- 文本 -->
                <span>{{item.authName}}</span>
              </template>
              <!-- 二级菜单 -->
              <el-menu-item :index=" '/' + subitem.path" 
                v-for="subitem in item.children"
                :key="subitem.id"
                @click="saveNavState('/' + subitem.path)">
                <template slot="title">
                  <!-- 图标 -->
                  <i class="el-icon-menu"></i>
                  <!-- 文本 -->
                  <span>{{subitem.authName}}</span>
                </template>
              </el-menu-item>
            </el-submenu>
          </el-menu>
        </el-aside>
        <!-- 右侧内容主体 -->
        <el-main>
          <!-- 路由占位符 -->
          <router-view></router-view>
        </el-main>
      </el-container>
    </el-container>
  </div>
</template>

<script>
export default {
  data(){
    return {
      // 左侧菜单数据
      menulist:[],
      // 是否这折叠
      isCollapse:false,
      // 被激活的链接地址
      activePath:''
    }
  },
  created(){
    this.getMenuList()
    this.activePath = window.sessionStorage.getItem('activePath')
  },
  methods:{
    logout(){
      window.sessionStorage.clear()
      this.$router.push('/login')
    },
    async getMenuList(){
      const {data:res} = await this.$http.get('menus')
      if(res.meta.status !== 200) return this.$message.error(res.meta.msg)
      this.menulist = res.data
      console.log(res)
    },
    // 点击按钮，切换菜单的折叠与展开
    toggleCollapse(){
      this.isCollapse = ! this.isCollapse
    },
    // 保存链接的激活状态
    saveNavState(activePath){
      window.sessionStorage.setItem('activePath',activePath)
      this.activePath = activePath
    }
  }
}
</script>

<style lang="less" scoped>
  #container{
    height: 100%;
  }
  .home-container{
    height: 100%;
  }
  .el-header{
    display: flex;
    justify-content: space-between;
    padding-left: 0;
    align-items: center;
    color: #fff;
    font-size: 20px;
    background-color: #373d41;
    > div{
      display: flex;
      align-items: center;
        span{
          margin-left: 15px;
        }
    }
  }
  .el-aside{
    background-color: #333744;
      .el-menu{
        border-right: none;
      }
  }
  .el-main{
    background-color: #eaedf1;
  }
  .toggle-button{
    background-color: #4a5064;
    font-size: 10px;
    line-height: 24px;
    color: #fff;
    text-align: center;
    letter-spacing: 0.2em;
    cursor: pointer;
  }
</style>